Shock absorber for spring suspended road vehicles



Dm w, 11935.. E'. WIELAND 2,023,943

SHOCK ASORBER FOR SPRING SUSPENDEDROAD VEHICLES Filed July l2, 1934Patented Dec. l0, 1935 UNITED STATES PATENT OFFICE EdouardY Wieland,Biel, Switzerland Applicationf July- 1.25.1934, Serial No- 734,835 InSwitzerland July 17, 1933 In spring suspended road vehicles shocks proaduced in passing over uneven places are transmitted to a considerableextent. td the vehicle frame. These shocks are more particularly no-Vticeable when passing over depressions, owing to what may be termed theafter effect. This is due more particularly to the fact that the carframe follows the vertical movements of the wheels and axles only with acertain lag so that frequently it drops very quickly when the Wheelshave already passed over the depression, and are-again moving upwards.Thus the main cause of shocks in passing over depressions or holes isdue to a temporary reduction in the supporting action o'f the springs,which allows the chassis to drop.

In passing over raised parts or projectings in the road, the reverseaction takes place, the supporting force of the springs beingtemporarily increased, with the result that the car frame is projectedupwardly.

Shock absorbers have been already proposed for the purpose of reducingor increasing the supporting force of car springs at the moment ofpassing over depressions and projections in they ro'ad, in which thewheel axles are connected to the upper part or body of the car by meansof a spring controlled system of levers; including a toggle joint, orwith a slide in the form of a double wedge movable to and fro in springshears.y As on bad roads the alternate up and down movements of thewheels caused by the unevenness of the road, follow each other veryquickly, more particularly at high speed, the reversing movementsproduce blows on all the parts of the shock absorber, so that, inparticular, parts sliding to and fro are exposed to rapid wear, andfreely oscillating springs are subject to risk of breakage. Shockabsorbers with partsv sliding to and fro' and those with freelyoscillating. Springe, have therefore o very Short life, are not veryreliable, and cannot be mounted in housings in a dust-proof manner.

The disadvantages of-the well known shock absorbing devices are avoidedby the improved shock absorber according to the present invention. Theinvention relates to a shock absorber of the well known kind in whichthe wheel axles are connected to the chassis by means o'f aspring-controlled lever which can swing about an axis out of a centralposition. The invention consists mainly in that the lever is held in itscentral position by spring means pressing in a direction towards thefree end o'f the said lever, and having at least one point of supportsitu- (Cl. 26T-20) ated between the ends of the lever. When the lever isswung out of its central position the said spring meansV acts laterallyon the lever in the direction of its swinging movement. Thus on thelever being rotated, a considerably greater component ioroe in thedirec-tion of rotation is obtained than with the already mentioned Wellknown absorbers. of this kind. that is to say a considerably improveddamping ofv shocks, coupled wtihthe advantage of a compact and simplemechanism which oen be easily erloloSed in e dust-prooiv manner, andthus be protected from the injurious action o'f dust,` dirt,V moisture,flying stones, etc. Qwing to the possibility of using guided springswhich act on a shocktaking place, l5 the lateral; oscillations cannothave an injurious effect on them. The, device remains reliable for along time, and is entirely no'iseless owing t othe rotaryv positivemovements of all the parts without sliding friction.

In order that the invention may be clearly understood, and readilycarried intopractice, two constructions of shock absorber according tothe invention are illustrated, by way of example only, in theaccompanying drawing.

In the drawing:-

Figure 1 is a side elevation of one construction of shock absorber withhalf of its casing removed.

Figure 2 is a section on the l'me ll--ll of Figure 1.

Figures 3 and 4. illustrate diagrammatically various lever and springpositions.

Figure 5 illustrates diagrammatically an alternative construction, and

Figure 6 is a shock diagram for the samestretch 35 of road when usingawell known type of shock absorber, and when using a shock absorberaccording to the present invention, thel full line showing the dampingaction `of the known shock absorber, and the dotted line showing theaction oi a shock absorber according toP the` present inf vention. adivided casing a, a lever bk is 'sea cured to a spindle c on which ismounted out-A side the` casing a lever e connected by means. of a rod dto a wheel axle. The casing a is secured to the car chassis or frame(not shown in the drawing) The freely oscillating upper end of the leverbis connected by means of a balance beam f to the upper ends of twospring guides g, h, of variable length on either side of the lever b,and pivoted to the beam f at 7. The lower parts h of the said springguides are pivoted about pins i arranged above the level of the spindlec. On the guides g, h are disposed helical compression springs k. Thepart of the casing a between the pins i, the guides g, h, and thebalance beam f form together an articulated parallelogram, the side f ofwhich is connected in the centre, but above the pivots 7, to the leverb; that is to say it can swing laterally with the latter towards eitherside, out of the central position. The part of the casing a between thepins i is immovable since it is part of the wall of the casing which isxed. The distance between the pivot pins i is slightly greater than thatbetween the pins j, so that the lever b is normally held by the springs7c in the central position or position of equilibrium. As soon as thewheel axle makes a downward movement relatively to the chassis due to adepression in the road (Figure 4), the lever b will be rotated out ofits central position to the right, whilst on passing over a projection,it will be rotated to the left. As the pivots fi, i andi, i of thesprings lc are situated intermediately between the ends ofthe lever 19,i. e. between planes parallelto each other passing through the saidends, the distance between the corresponding pairs of pivots i and imust increase, which is readily permitted, since, as already stated, theguides g, h are of variable length, being formed by ycup-shaped partsslidable on one and the same rod.

Thus on the hinged parallelogram being moved out of its position ofequilibrium, the pivot points y' at each side of the lever b will moveaway from the pivot points i. It follows from this that the shockabsorber springs 1c, which are stressed to the greatest extent in theposition of equilibrium, will come into action with an increasinglateral fshock angle, that is to say will expand, on the hingedparallelogram moving out of its central position. Owing to the distancebetween the corresponding pivots y and i being smaller than the distancebetween the pivots of the lever b', the angular deection of the parts g,h is greater than that of the lever b, so that the expanding springs kexert on the lever b a lateral force tending to increase its deflection.

The subsequent rebound of the wheel axle must then overcome the force ofthe springs 7c, owing to which the intensity of the shock transmitted tothe chassis is damped. As the springs k are held by guides and subjectto compression they cannot set up lateral oscillations under the actionof the veryV quick successive movements to and fro or deflections, whichoscillations may involve great risk of breakage for the springs.

In the alternative constructions illustrated diagrammatically in Figure5, the balance beam f is omitted, and the springs It are brought closertogether in front of and behind, the lever b, and are connected directlywith the oscillatingor free end of the latter. The springs are shorter ithan the lever b, and their lower ends are mounted intermediatelybetween the ends of the lever on pivot pins i projecting inwardly fromthe Walls of the casing a, and arranged either in the vertical plane ofthe spindle c or on both sides, and close to it. The action of thesprings 1c on the lever b is exactly the same as in the costructionpreviously described and illustrated by Figures 1 4. The construction ishowever, considerably simpler, the oscillating masses are smaller, andthe casing could also be made somewhat smaller, which is a greatadvantage having regard to the compactness of construction necessaryowing to the limited space available in motor vehicles. The casing a maybe lled with oil or grease so as always to ensure an easy mobility ofall the moving parts.

rWhat I claim is:-` A 1. Shock absorber means for spring suspendedwheeled vehicles including a spindle revoluble on an axis iixedlypositioned with respect to the frame of the vehicle, means connectingthe spindle toa wheel axle of the vehicle to rotate the spindle as theaxle moves toward and from the vehicle'frame, a lever I'lxed on saidspindle and projecting ,radially therefrom, a balance Abeam pivoted atits center to the upper end of said lever to swing aboutl an axisparallel to the axis of the spindle, and springseach having one endconnected to a respective end of said balance beamY andv urging saidbalance beam end away from saidA spindle.

2. Shock absorber means for spring suspended wheeled vehicles includinga spindle revoluble on an axis xedly positioned with respect to theframe of the vehicle, means connecting the spindle to a wheel axle ofthe vehicle to rotate the spindle as the axle moves toward and from thevehicle frame, a lever fixed on said spindle and projecting radiallytherefrom, a balance beam pivoted at its center to the upper end of saidlever to swing about an axis parallel to the axis of the spindle,springs each having one end connected to a respective end of saidbalance beam and urging said balance beam end away from said spindle,and pins positioned on opposite sides of said lever in xed relation tothe vehicle frame and having the remaining ends of said springs attachedthereto.

3. Shock absorber means for spring suspended wheeled vehicles includinga spindle revoluble on an axis xedly positioned with respect to theframe of the vehicle, means connecting the spindle to a wheel axle ofthe vehicle to rotate the spindle as the axle moves toward and from thevehicle frame, a lever xed on said spindle and projecting radiallytherefrom, a balanceV beam pivoted at its center to the upper end ofsaid lever to swing about an axis parallel to the axis of the spindle,Vsprings each having one end connected to arespective end of said balancebeam and urging said balance beam end away from Ysaid spindle, and pinspositioned on opposite sides of said lever in fixed relation to thevehicle frame and' having the rremaining ends of said springs EDOUARDWIELAND.

